1. Field of Invention
In the field of surgery, this invention relates to a safety device for handling and advancing a safe trochar through a patient's soft tissue, including the dermal layers.
2. Description of Prior Art
The implementation of safety measures in the workplace of health-care personnel, such as physicians, nurses and phlebotomists, has lagged behind such implementation in other industries. Nurses have been concerned with hazards posed by sharp devices associated with their practices and have joined other medical practitioner groups to push for safer hardware, workplace environments, and injury reporting. As an answer to the problem, in the 1990s several states enacted laws concerning health-care worker safety. In 2000, the President of the United States signed into effect the “Needlestick Safety and Prevention Act” (H. R. 5178) requiring health-care facilities to use “Safe Medical Devices”. A limited number of devices are now available that diminish the exposure of health-care personnel to scratches and puncture wounds and contamination by potentially dangerous body fluids or chemicals which may lead to infection. Such pathogens as HIV, Hepatitis B, Hepatitis C, staphylococcus and streptococcus bacteria and others, may be transferred from the patient to health-care workers by scratches and puncture wounds. The American Nurses Association (ANA) reports that more than twenty diseases can be transmitted through sharps or needlestick injuries. The newly available devices include convenient safety sheaths around hypodermic needles and intravenous medication bottles. The nature of surgical procedures, however, unavoidably exposes medical personnel, including surgeons, assistants, and nurses, to many other sharp and potentially injurious instruments. The instruments include not only needles, but also trochars, scalpels, retractors and many other sharp and pointed tools. The National Institute for Occupational Safety and Health (NIOSH) reports that “while the exact number of needlestick injuries is not available, it is estimated there are 600,000 to 1,000,000 needlestick injuries in the United States per year, resulting in up to 1,000 new cases of HIV, Hepatitis B or Hepatitis C annually.”
One of the most dangerous of sharp instruments used in surgery is the trochar; an elongated, highly polished spear-like instrument, utilized, amongst other purposes, to make stab wounds in soft tissue for the placement of surgical drains. Until the hardware of the present invention, no safe trochar has been available.
Surgical drains are used in a wide variety of surgical procedures. The drains are tubular and made of soft materials; plastics and rubbers being common. One end of such a drain is placed in a body cavity and the other end extends outside of the patient's body. The drain exits the body through a stab wound, created by a trochar, in the soft tissue through the skin. The drain carries fluids into a reservoir attached to the other end of the drain tube. The drain facilitates the removal of an unwanted collection of fluid, including serum, blood, bile and/or waste materials such as pus. In addition to conducting waste materials, drains may serve as salvage devices. In a procedure known as “autologous transfusion”, using drains after deep tissue surgery, blood may be collected, washed or unwashed, and transfused into the patient's body.
It will be appreciated from the above, that many surgical drains are installed daily. Since most surgical drains are inserted through the skin with trochars, it is obvious that a safe trochar is a much-needed device. Before the hardware of this invention, no trochar was available which provided built-in safety features for installing surgical drains. In this invention, a safe trochar is provided. The hardware of this invention also provides a safety guide for enhancing the handling of this safety trochar and for protecting OR personnel.
Trochars often have plastic protective sheaths when presented to the sterile field in the Operating Room. Such a protective sheath covers the trochar's sharp point and reduces damage during shipping and handling. The removal of the plastic protective sheath, necessary prior to use of the trochar, is a bit tedious. Often times, the plastic sticks to the trochar and resists removal. When it does finally slide off, the resulting sudden reaction causes the protective sheath to go in one direction and the trochar in another. The sharp point may contact something or someone in the process. The sharp point may be damaged, or someone may be cut or stabbed. The hardware of this invention provides a protective sheath that is installed before shipping. This protective sheath is on the safety trochar as presented into the sterile field. But, OR personnel do not have to remove this protective sheath; the trochar automatically slides out of the sheath by action of the safety guide.
The sharp points of trochars are available in several different designs. One design has three flat surfaces (facets) evenly spaced around the diameter of the rod and angled so that the surfaces come to a point at end of the rod, on the rod's linear axis. Another design has only two flat surfaces leaving intact a portion of the original radius of the rod. In both three facet and two facet point designs, the flat surfaces intersect to form a ridge. This ridge is sharp enough to cut tissue when enough pressure is exerted. In fact, the cutting of the tissue by the ridge between the facets reduces the force required to drive the trochar through soft tissue. Another design of the sharp point of trochars is a simple cone. The force required to push a cone point trochar through soft tissue is somewhat greater than that required to push a faceted sharp point through soft tissue. However, there are advantages to a cone point trochar. A hole pierced with a cone point appears to show less evidence of trauma to the surrounding tissue than one pierced with a faceted point. Yet a different point design has a compound cone: two or more cone angles are utilized, sequentially, along the point. There are about a dozen sharp point designs in trochars. The safety hardware of this invention is designed to work with, if not all, at least a majority of the designs.
Formerly, trochars were handled manually. Until the hardware of this invention, there was no safety device available to protect surgical personnel from sticks and scratches from trochars used for placing drains and for similar through-the-tissue passage. The sharp instrument was grasped, directed and advanced by hand. The surgeon wears gloves. The trochar is a highly polished, hard thin rod. The environment is slippery. Often, visibility is obscured. Pushing a trochar through tissue can require some force. Any force, rotational or linear must be obtained through friction between wet, bloody gloves and wet slippery metal. So, the grip by the surgeon's hand onto the trochar must be significantly high. The higher grip required was fatiguing. Fatigue leads to errors. The hardware of this invention serves as a handle for the trochar. The handle holds the trochar firmly and the handle is shaped to fit the surgeon's hand without slipping. No slipping means less gripping force required and therefore, less fatigue.
Most trochars have a curve at the mid-length of the rod. The pointed end (herein called the first end) is at an angle to the butt (opposite) end (herein called the second end). The first end is built upon a right circular cylinder, as is the second end. Joining these two straight rod ends is a curve. The result is an instrument that looks somewhat like a sailmaker's needle. The curve in the trochar allows a more normal (right angle) angle of contact between the sharp pointed “piercing end” of the instrument and the tissue, because the angle allows the second end to clear obstructions in close spaces. Formerly, as described above, installing a surgical drain, or performing other procedures requiring a rod-like sharp instrument, required holding the instrument by hand and exposing surgical personnel to the sharp pointed end of that instrument; before, during and after the instrument had been through the tissue of the patient. Former trochars had no “indicators” on the second end to tell the surgeon where the pointed end (which is hidden) was directed. It was patently hazardous to have the point emerge in an unexpected place. The hardware of this invention provides a safety guide that by design holds the safety trochar in such a manner so that the surgeon knows exactly where the trochar is pointing.
A trochar for drain placement typically enters the patient's soft tissue from inside the body cavity and exits to the outside through the overlying skin. Great care must be taken in avoiding injury to vital structures while the trochar is being inserted. Great care must also be taken to avoid driving the sharp end into oneself or an assistant as it exits the soft tissue. There is a layer of adipose tissue inside the body, beneath the dermal layers. This fat layer may be as thin as 10 mm but often is much thicker; it is not uncommon to encounter 75 mm or even thicker. Since the trochar is curved, and since it is being held on the second end, the sharp point tends to deflect away from the tissue when any resistance is encountered. The instrument revolves within the surgeon's slippery gloved hand, the point on the curved end aiming in a new direction. Unfortunately, before now, there has been no target mechanism to tell the surgeon where the sharp point of the trochar will emerge from the tissue. So, the sharp point may poke through where it is not expected, where it is not wanted. If the hand backing up the tissue is where the point emerges, then, the surgeon or assistant is impaled. On its way through the patient's tissue, the trochar becomes coated with body fluids from the patient and this must be considered hazardous. The hardware of this invention provides a target so that the surgeon knows exactly there the point will emerge from the soft tissue.
It is necessary to hold tissue through which a sharp instrument is being driven. Holding the tissue prevents slipping. Holding also reduces stretching the tissue. But, with previous sharp angled instruments it was difficult to know where the sharp point would emerge. A good method of “backing up” the tissue right in the path of the trochar, was needed. The hardware of this invention provides a target which not only indicates exactly where the sharp point is aimed, this target also provides a support, a back up system to hold the tissue as the sharp point is being advanced through it.
When the sharp point emerges after passing through the tissue, the trochar must be pulled all the way through the tissue, followed by some of the drain tube. The trochar is hard, highly polished and is made even more slippery by body fluids picked up in passing through the patient's tissue. Of course, grasping the pointed end with gloved fingers is not a very good method of pulling the trochar, at least not initially. How does one grasp a slippery cone at the pointed end? Therefore, the surgeon or assistant needed to pick up a grabber like a forceps or pair of pliers. However, the pliers and forceps are also hard and well polished. The result is that the task of grabbing and pulling a sharp-pointed, hazardously coated, slippery rod requires some force and a lot of care. With the hardware of this invention, the sharp point of the safe trochar automatically enters the target assembly. Further, the safe trochar of this invention is automatically guided into the safety sheath, upon protruding from the soft tissue, and it is locked therein. The safety guide provides an ergonomically correct handle for effortlessly pulling the captured trochar the rest of the way through the tissue.
Formerly, after pulling the used trochar through the soft tissue, a surgeon had to hold the trochar in his gloved hand and cut it free from the drain tube. The sharp point of the trochar was exposed and it was wet and hazardous. With the hardware of this invention, the trochar sharp point is safely locked into the sheath, completely harmless.
A further feature of this hardware is that the trochar may not be used a second time. The safety guide will not re-open and expose the sharp point of a used trochar. When the guide is closed, there is no way to release the trochar a second time from the safety sheath.